Ammonium Chloride → 1,4a,5,7a-Tetrahydrocyclopenta [c] pyrane-4-carboxylic acid methylester

HRID 1976371Notes

Reaction equation

[CH3:1][O:2][C:3]([C:5]1[C@H:6]2[CH2:19][CH:18]=[C:17](C=O)[C@@H:7]2[C@H:8](OC(OCC)C)[O:9][CH:10]=1)=[O:4].C(Br)CCCC.[Mg].[Cl-].[NH4+]>O1CCCC1>[CH3:1][O:2][C:3]([C:5]1[CH:6]2[CH2:19][CH:18]=[CH:17][CH:7]2[CH2:8][O:9][CH:10]=1)=[O:4]

Participants

Conditions

Temperature: -78 °C

Procedure

1.55 g of (1S,4aS,7aR)-1-[1-(ethoxy) ethoxy]-7-formyl-1,4a,5,7a-tetrahydrocyclopenta [c] pyrane-4-carboxylic acid methylester were dissolved in anhydrous tetrahydrofuran, followed by dropping 20 ml of magnesium pentylbromide (0.3 M tetrahydrofuran solution) while stirring and cooling at −78° C., and then stirring for 4 hours at the same temperature. After addition of saturated aqueous ammonium chloride solution to the reaction mixture, it was extracted with ethyl acetate. After washing the organic phase with brine, it was dried over magnesium sulfate. After distilling off the solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain a colorless oil from the hexane-ether eluate in the form of (1S,4aS,7aR)-1-[1-(ethoxy) ethoxy]-7-(2-hydroxy)-n-hexyl]-1,4a,5,7a-tetrahydrocyclopenta [c] pyrane-4-carboxylic acid methylester (1.46 g, yield: 76%). The physicochemical properties of this compound are described below.

Workup

stirringstirring for 4 hours at the same temperature
extractionwas extracted with ethyl acetate
washAfter washing the organic phase with brine, it
dry with materialwas dried over magnesium sulfate
distillationAfter distilling off the solvent under reduced pressure
customthe residue was purified by silica gel chromatography

Sources & evidence

ORD record: ord-fdd4329b137a4e65a826f98f7da5efa6
Source dataset: uspto-grants-2001_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06225478B1

Reaction notes

Loading…